In wireless communication systems, it is desirable to reduce overhead associated with signaling for voice and data services, system information, control, etc. In traditional GSM and UMTS systems, bearer establishment is enabled through dedicated signaling. The bearer defines radio parameters, for example, time slot, frequency, code, etc., associated with a channel during a call. In voice communications for example a dedicated channel is assigned to each user. In High Speed Downlink Packet Access (HSDPA) systems, transport format and modulation/coding parameters (TFRI) are provided using dedicated control signaling on a shared control channel, wherein the shared control channel also signals the code channel assigned to the user.
In some data only (DO) systems, voice is served over IP (VoIP). It is known to improve such systems for VoIP traffic using hybrid automatic repeat request (HARQ) error correction schemes and smaller packet sizes. While VoIP users have the same benefits of advanced link adaptation and statistical multiplexing as data users, the greatly increased number of users that may be served because of the smaller voice packet sizes places a burden on control and feedback mechanisms of the system. It can be easily envisioned, for example, that 30 times as many voice packets could be served in a given frame than data packets. There are typically about 1500 bytes for data and about 40-50 bytes for voice. Present resource allocation and channel quality feedback and acknowledgment mechanisms however are not designed to handle such a large number of allocations.
In 802.16e systems, it is known to use a telescoping control channel that expands to include as many assignments as necessary for resource allocation. However, such an expansion mechanism does not address feedback or the fact that the entire downlink may be consumed for control information. Another mitigating mechanism is to group several voice packets together for transmission to a particular user. Unfortunately, this sort of packaging mechanism can adversely affect speech quality when a transmission is not received, since longer periods of speech are lost or corrupted. Thus there is a need for increasing the number of VoIP users supported while reducing control and feedback overhead. In packet based systems the term “data” is meant to signify payload information for any service, voice or data.
The various aspects, features and advantages of the present disclosure will become more fully apparent to those having ordinary skill in the art upon careful consideration of the following Detailed Description thereof with the accompanying drawings described below. The drawings may have been simplified for clarity and are not necessarily drawn to scale.